a parade, big name entertainment, and a whole lot more! the story coming up here on wjz. ,, >>> it's 5:30. 88 degrees and sunny. good evening, and thank you for staying with wjg eyewitness news. here's some. stories people are talking about tonight. when does good air go bad? nasa is searching for the answer using a low-flying plane over maryland. alex reports the first flight took wing today. >> reporter: maybe you saw it, flying at only 1,000 feet. this plane converted by nasa scientists into a flying laboratory, studying air quality between washington, d.c. and grace. >> in the long run, this will be able to help protect public health. >> nasa already uses satellites to track pollutions. they're good at seeing what is happening really high up. but. >> unfortunately the satellites now are not really good enough to diagnose what is at surface levels versus what is higher in the atmosphere. >> and for people the action is closer to the ground. pollution levels generated by cars, coal burning power plants is at best a guess for satellites.